Multiplexed ChIP-Seq Sample Preparation

Transcription

1 Multiplexed ChIP-Seq Sample Preparation Contents 1 Component Information 2 General Recommendations 3 Prepare Multiplex Adapters and PCR Primers 5 Perform End Repair 6 Add ʻAʼ Bases to the 3' End of the DNA Fragments 8 Ligate Adapters to DNA Fragments 9 Size Select the Library: 2% Agarose Gel Size Selection 11 Size Select the Library: Pippin Prep Size Selection 15 Enrich the Adapter-Modified DNA Fragments by PCR 17 Validate the Library

2 Component Information Reagents: A kit containing all reagents and oligos for library preparation can be purchased from Illumina: ChIP Seq DNA Sample Prep Kit (Illumina IP ) A kit containing all reagents, except the Adapter Oligo Mix and PCR Primers, can be purchased from NEB. Adapter and Primers can be made by following the protocol on pages 3-4: NEBNext ChIP-Seq DNA Sample Prep Reagent Set 1 (NEB E6200S/L) NEBNext ChIP-Seq DNA Sample Prep Master Mix Set 1 (NEB E6240S/L) Individual Reagents, if you want to purchase each separately: 10X T4 DNA Ligase Buffer with 10 mm ATP (NEB B0202S) T4 DNA Polymerase (NEB M0203S) Klenow DNA Polymerase (NEB M0210S) T4 Polynucleotide Kinase (PNK) (NEB M0201S) 10 mm dntps Mix 1 mm datp Klenow Fragment (3' to 5' exo minus) (NEB M0212S) Quick DNA Ligation Kit (NEB M2200S) Phusion HF DNA Polymerase (NEB M0530S/L) OR Phusion HF DNA PCR Kit (NEB E0553S/L) OR Phusion HF PCR Master Mix (NEB MO531S/L) Gel Purification Components: 6X Loading Dye (NEB B7021S) Low Molecular Weight DNA Ladder (NEB N3233L) Certified Low Range Ultra Agarose (Bio Rad ) SYBR Gold Nucleic Acid Gel Stain (Invitrogen S-11494) Roche Restriction Enzyme Buffer H Gel x-tracta (USA Scientific ) QIAquick Gel Extraction Kit (QIAGEN 28704) TaKara DNA-OFF (TaKara 9036) DNA Purification Kits: QIAquick PCR Purification Kit (QIAGEN 28104) MinElute PCR Purification Kit (QIAGEN 28004) Agencourt AMPure XP Beads - 5 ml (Beckman Coulter A63880) Equipment Needed: Centrifuge, Vortexer, common lab equipment Heat Block/Dry Bath/Water Bath set at 20 o C and 37 o C PCR Machine Magnetic Stand (Invitrogen s DynaMag2, D) Dark Reader transilluminator (ISC BioExpress U ) o For 2% Agarose Gel Size Selection Pippin Prep (Sage Science or Life Technologies) o Pippin Prep 2% EF Gels (Life Technologies or Sage Science CEF-2010) Agilent 2100 BioAnalyzer o DNA-1000 Kit (Agilent ) 1

3 General Recommendations Before Beginning the ChIP Procedure: Do not block the ChIP with Salmon Sperm or trna. It will be sequenced. Use BSA. Everything depends on the antibody used. All antibodies are different, so varying results are to be expected between ChIPing for different histone modifications and transcriptional factors. For most transcriptional factors it can be difficult to obtain a good library, while for the majority of histone modifications it is easy. In addition, verify that the ChIP worked by doing QPCR with a positive control. Do Q-PCR and quantify enrichment relative to non-specific genomic sequence and Input. For example, use primers to the 28S gene as a non-specific sequence, and calculate enrichment from C T s as follows: 2^[(28S ChIP - YourGene ChIP ) - (28S Input - YourGene Input )]. Make sure to avoid any contamination. Use clean fresh buffers and sterile water. Any contaminant DNA that gets into your ChIP sample will be sequenced. Make sure to have good sonication of the chromatin before doing the ChIP (below). If there is not a decent amount of gdna in the bp range, then that could lead to low yield in the library prep. Troubleshoot multiple different conditions to find the right sonication protocol. Good Sonication Before Beginning the ChIP-Seq Protocol: An Input sample should be run as a Positive Control, as this should achieve a library every time. The purification steps in this procedure are written to ensure maximum yield each time. Take care at each purification step. Keep in mind each step loses approximately 20% of the DNA each time. Ethidium Bromide (EtBr) and UV light degrades and damages the DNA library. Thus it is safer to use Sybr Gold instead of EtBr and use the Dark Reader Transilluminator instead of a Gel dock. This protocol is setup to be a catch-all procedure, providing steps for any purchased kit, multiple DNA purifications options, and DNA size selection options. 2

4 Prepare Multiplex Adapters and PCR Primers Adapters and primers can be ordered from Operon/IDT. Follow our helpful information below to get better results. Order the adapters PAGE purified. Order the PCR primers HPLC or PAGE purified. The * stands for phosphorothioate bond, which helps protect against endonuclease activity and has a stronger bond. Adapter and Primer preparation are on page 4. All sequences are written 5 to 3. The resulting library can be used for Multiplexed, Paired End, and Single Read sequencing. Some sequencing experiments require the use of fewer than 12 index sequences in a lane with a high cluster density. In such cases, a careful selection of indexes is required to ensure optimum cluster discrimination by having different bases at each cycle of the index read. Illumina recommends the following sets of indexes for low-level pooling experiments. 2 Samples: Indexes 6 and 12 3 Samples: Indexes 4, 6, and 12 4 Samples: Indexes 4, 6, 12, and 23 5 Samples: Indexes 4, 5, 6, 12, and 23 6 Samples: Indexes 2, 4, 5, 6, 7, and 12 Multiplexing Adapters: MP_Adapt1: OP: [Phos]GATCGGAAGAGCACACGTC*T IDT: /5Phos/GATCGGAAGAGCACACGTC*T MP_Adapt2: ACACTCTTTCCCTACACGACGCTCTTCCGATC*T Multiplexing PCR Primer 1: AATGATACGGCGACCACCGAGATCTACACTCTTTCCCTACACGACGCTCTTCCGATC*T Multiplexing PCR Primer 2: Order one Index per sample. Primer Name _Index 1 _Index 2 _Index 3 _Index 4 _Index 5 _Index 6 _Index 7 _Index 8 _Index 9 _Index 10 _Index 11 _Index 12 _Index 23 PCR Primer2 Sequence (each containing a different Index) CAAGCAGAAGACGGCATACGAGATCGTGATGTGACTGGAGTTCAGACGTGTGCTCTTCCGATC*T CAAGCAGAAGACGGCATACGAGATACATCGGTGACTGGAGTTCAGACGTGTGCTCTTCCGATC*T CAAGCAGAAGACGGCATACGAGATGCCTAAGTGACTGGAGTTCAGACGTGTGCTCTTCCGATC*T CAAGCAGAAGACGGCATACGAGATTGGTCAGTGACTGGAGTTCAGACGTGTGCTCTTCCGATC*T CAAGCAGAAGACGGCATACGAGATCACTGTGTGACTGGAGTTCAGACGTGTGCTCTTCCGATC*T CAAGCAGAAGACGGCATACGAGATATTGGCGTGACTGGAGTTCAGACGTGTGCTCTTCCGATC*T CAAGCAGAAGACGGCATACGAGATGATCTGGTGACTGGAGTTCAGACGTGTGCTCTTCCGATC*T CAAGCAGAAGACGGCATACGAGATTCAAGTGTGACTGGAGTTCAGACGTGTGCTCTTCCGATC*T CAAGCAGAAGACGGCATACGAGATCTGATCGTGACTGGAGTTCAGACGTGTGCTCTTCCGATC*T CAAGCAGAAGACGGCATACGAGATAAGCTAGTGACTGGAGTTCAGACGTGTGCTCTTCCGATC*T CAAGCAGAAGACGGCATACGAGATGTAGCCGTGACTGGAGTTCAGACGTGTGCTCTTCCGATC*T CAAGCAGAAGACGGCATACGAGATTACAAGGTGACTGGAGTTCAGACGTGTGCTCTTCCGATC*T CAAGCAGAAGACGGCATACGAGATCCACTCGTGACTGGAGTTCAGACGTGTGCTCTTCCGATC*T Index ATCACG CGATGT TTAGGC TGACCA ACAGTG GCCAAT CAGATC ACTTGA GATCAG TAGCTT GGCTAC CTTGTA GAGTGG 3

5 Prepare Multiplex Adapters and PCR Primers (cont.) Prepare the Adapters 1. Dilute MP_Adapt1 and MP_Adapt2 to 100µM in EB. 2. Mix the following reagents in a PCR Tube: x1 MP_Adapt1 20 µl MP_Adapt2 20 µl NEB Buffer 2 10 µl 50 µl 3. Incubate in a thermal cycler with the following program: 95 o C 5min 80 o C 1min 70 o C 1min 60 o C 1min 50 o C 1min 40 o C 1min 30 o C 1min 25 o C Alternatively, Incubate at 95 o C for 5min in a heat block and then remove the block and put on the bench for 2-3hrs. 4. The final molarity of the Multiplexing Adapter Mix is now approximately 40µM. 5. Dilute the Multiplexing Adapter Mix 1:20 in EB, for a final molarity of ~2µM. This is the molarity needed for ligation. Prepare the Primers 1. Dilute all the PCR Primers to 25µM in EB. Do not dilute below 25µM. If necessary, the primers can have a higher molarity of 50µm. 4

6 Perform End Repair This protocol converts the overhangs into phosphorylated blunt ends, using T4 DNA polymerase, E. coli DNA Pol I large fragment (Klenow polymerase), and T4 polynucleotide kinase (PNK). The 3' to 5' exonuclease activity of these enzymes removes 3' overhangs and the polymerase activity fills in the 5' overhangs. Use all 40µl of ChIP DNA. Dilute 10ng Input DNA in 40µl water. Cleanup Method QIAquick PCR Purification Kit Sample Prep Kit Components T4 DNA ligase buffer with 10mM ATP 10mM dntps mix T4 DNA polymerase Klenow DNA polymerase T4 Polynucleotide Kinase (PNK) Master Mix (MM) Kit Components End Repair Reaction Buffer End Repair Enzyme Mix Procedure 1. Prepare the following reaction mix: x1 x5 Water 0.8 μl 4 µl T4 DNA ligase buffer 5 μl 25 µl 10mM dntp mix 2 μl 10 µl T4 DNA polymerase 1 μl 5 µl T4 PNK 1 μl 5 µl Klenow DNA polymerase 0.2 μl 1 µl 10 μl 2. Add 10 µl of reaction mix to 40 µl DNA OR MM: Add 5 µl of End Repair Reaction Buffer and 1µl End Repair Enzyme Mix to 44 µl DNA 3. Incubate for 30 minutes at 20ºC. 4. Purify using QIAquick PCR Purification Kit: Add 250 µl Buffer PB and mix by pipetting Apply to column and spin at max speed 30 sec Pour flowthrough back on to column and spin at max speed 30 sec Add 750 µl Buffer PE and spin at max speed 45 sec Spin empty column at max speed 1 min Transfer column to new 1.5 ml tube Aspirate around clear ring inside column Allow to air dry 1 min Apply 36 µl Buffer EB and let stand 2 min (accounts for loss of 2 µl volume during elution) o MM: Elute in 46 µl EB Spin at max speed 1 min and discard column 5

7 Add ʻAʼ Bases to the 3' End of the DNA Fragments This protocol adds an ʻAʼ base to the 3' end of the blunt phosphorylated DNA fragments, using the polymerase activity of Klenow fragment (3' to 5' exo minus). This prepares the DNA fragments for ligation to the adapters, which have a single ʻTʼ base overhang at their 3' end. Cleanup Method MinElute PCR Purification Kit Sample Prep Kit Components Klenow buffer (NEB buffer #2) 1mM datp Klenow fragment (3' to 5' exo minus) Master Mix (MM) Kit Components Klenow fragment (3' to 5' exo minus) da-tailing Reaction Buffer (10x) Procedure 1. Prepare the following reaction mix: x1 x5 Klenow buffer (NEB buffer #2) 5 μl 25 µl 1mM datp 10 μl 50 µl Klenow exo (3ʼ to 5ʼ exo minus) 1 μl 5 µl 16 µl 2. Add 16 µl of reaction mix to 34 µl DNA sample from previous step. OR MM: Add 5 µl of da-tailing Reaction Buffer and 1 µl of Klenow exo to 44 µl DNA from previous step 3. Incubate for 30 minutes at 37ºC. 4. Purify using MinElute PCR Purification Kit: Add 250 µl Buffer PB and mix by pipetting Apply to column and spin at max speed 30 sec Pour flowthrough back on to column and spin at max speed 30 sec Add 750 µl Buffer PE and spin at max speed 45 sec Spin empty column at max speed 1 min Transfer column to new 1.5 ml tube Aspirate around purple ring inside column Allow to air dry 1 min Apply 15 µl Buffer EB and let stand 2 min (accounts for loss of 2 µl volume during elution) o MM: Elute in 21 µl of EB Spin at max speed 1 min and discard column 6

8 Ligate Adapters to DNA Fragments This protocol ligates adapters to the ends of the DNA fragments, preparing them to be hybridized to a flow cell. Final Adapter mix molarity should be 1.5-2µM. Follow step 6a for the optimum cleanup option to avoid adapter junk (see Bad Library on pg.17). The Ampure XP Beads have a size cutoff of 100bp and thus eliminate any adapter that has been ligated to itself (~60bp) aka adapter junk. This adapter junk will stick around after size selection and will be PCRed, so this is the ideal time to get rid of it. If Agencourt Ampure XP Beads are not available then follow step 6b. The QIAquick PCR Column also has a cutoff of 100bp, but still allows some of the adapter junk through. The QIAquick Column purification takes only ~15min, while the Ampure XP Bead purification takes ~30min. DO NOT use Qiagen s MinElute column, as it will result in a Bad Library with adapter junk. Cleanup Method Agencourt Ampure XP Beads Freshly prepared 75% Ethanol Optional: QIAquick PCR Purification Kit Sample Prep Kit Components 2X Quick DNA ligase buffer Adapter oligo mix (either Illumina s or Multiplexing Adapter Mix) Quick T4 DNA ligase Master Mix (MM) Kit Components 5X Quick DNA ligase buffer Adapter oligo mix Quick T4 DNA ligase Procedure 1. Remove the Ampure XP Beads from 4 o C and let sit at Room Temp for ~30min. 2. If you have not done so, dilute Illumina s Adapter 1:10 in EB OR Multiplexing Adapter 1: Prepare the following reaction mix: x1 x5 2X Quick DNA ligase Buffer 15 μl 75 µl Diluted Adapter oligo mix 1 μl 5 µl Quick DNA ligase 1 μl 5 µl 17 µl OR MM: x1 x5 5X Quick DNA ligase Buffer 6 μl 30 µl Diluted Adapter oligo mix 1 μl 5 µl Quick DNA ligase 4 μl 20 µl 11 µl 4. Add 17 µl of reaction mix to 13 µl DNA sample from previous step. OR MM: Add 11 µl of reaction mix to 19 µl of DNA sample from previous step. 5. Incubate for 15 minutes at 20ºC. 7

9 Ligate Adapters to DNA Fragments (cont.) 6a. Purify using Agencourt Ampure XP Beads: Make sure beads come to Room Temp before proceeding Vortex/mix the beads until they are well dispersed, and keep doing so every couple of samples Add 50 µl of mixed Ampure XP beads and mix by pipetting at least 10x Incubate the tubes at Room Temp for 12 min Place tubes on magnetic stand and let sit for 2 min or until the liquid appears clear Remove and discard 75 µl of the supernatant from each tube Add 200 µl 75% Ethanol and let it incubate on the stand for 1 min and then Discard Ethanol Repeat Ethanol wash one more time, making sure to completely remove all traces of Ethanol Let stand at Room Temp for 5-10 min to dry and remove all Ethanol Remove from magnetic stand and resuspend the dried beads in 11 µl EB for 2% Agarose Gel o For Pippin Prep elute in 31 µl EB Mix by pipetting 10x and Incubate at Room Temp for 5 min. Place tubes on magnetic stand and let sit for 2 min or until the liquid appears clear Transfer 10 µl of the supernatant to a new tube for 2% Agarose Gel procedure o Transfer 30 µl of the supernatant to a new tube for Pippin Prep procedure 6b. Purify using QIAquick PCR Purification Kit: Optional Add 150 µl Buffer PB and mix by pipetting Apply to column and spin at max speed 30 sec Pour flowthrough back on to column and spin at max speed 30 sec Add 750 µl Buffer PE and spin at max speed 45 sec Spin empty column at max speed 1 min Transfer column to new 1.5 ml tube Aspirate around clear ring inside column Allow to air dry 1 min Apply 32 µl Buffer EB and let stand 2 min (accounts for loss of 2 µl volume during elution) Spin at max speed 1 min and discard column Size Select the Library This protocol removes excess adaptors and selects a size range of templates to go on the Cluster Station. There are many ways to do size selection. Running a normal 2% Agarose Gel and Sage Science s Pippin Prep are highlighted in this protocol. In addition, Invitrogen s E- Gel SizeSelect 2% Agarose gels or Caliper s Caliper XT can be used, but not mentioned in this protocol. 8

10 2% Agarose Gel Size Selection Components Certified Low Range Ultra Agarose 50X TAE buffer Low Molecular Weight DNA ladder 6X loading dye 10X Roche Buffer H SYBR Gold QIAquick Gel Extraction Kit Gel x-tracta (USA Scientific ) TaKara DNA-OFF (TaKara 9036) Procedure 1. Make sure to have previously washed the gel tray, combs, cutting glass, etc. with DNA Off before proceeding. 2. Dilute 50X TAE Buffer to 1X TAE Buffer in 500 ml (10ml of 50X TAE into 490 ml of dih 2 O). 3. Prepare a 50 ml, 2% agarose gel with 1X TAE buffer and Ultra Low Agarose. Do not add EtBr or any DNA stain. 4. Dilute SYBR Gold 1:1000 in water (add 0.5 µl to 500 µl water) 5. Prepare the DNA ladder mix: x1 x2 Diluted SYBR Gold 10 μl 20 µl 6X loading dye 3.75 μl 7.5 µl 10X Roche Buffer H 1.25 μl 2.5 µl Low Mol. Weight ladder 2.5 µl 5 µl 17.5 µl 35 µl 6. Prepare the loading dye mix: x1 x5 6X loading dye 3 μl 15 µl 10X Roche Buffer H 2 μl 10 µl 5 µl 7. Add 5 µl of loading dye mix to each DNA sample from previous step. 8. Load 17 µl of DNA ladder mix to outside wells. 9. Load entire sample (~15 µl) on gel leaving an empty lane between samples to avoid cross contamination. 10. Run gel at 100 V for 45 minutes. 11. View the gel on a Dark Reader transilluminator. Do not expose gel to UV light. 12. Using a Gel x-tracta or clean razor for each lane, excise a region of gel just above the 200bp band in the 220 ±25 bp range for Genomic DNA Adapters (or bp range for Multiplexed Adapters). In addition, excise a region just above the first cut (i.e, 250 ±25 bp for Genomic DNA Adapters), to save as a backup for just in case there are PCR issues or one may get a better result with a higher insert. Cut out as many bands as desired, just make sure they are small and not below 180bp. DO NOT cut a wide range or a big piece. Photograph the gel after excisions for reference later. 9

11 2% Agarose Gel Size Selection (cont.) 13. Purify DNA from gel slices using the QIAquick Gel Extraction Kit. Weigh empty 1.5 ml tube to zero scale Weigh each tube containing gel piece To each tube add 6 volumes of Buffer QG per volume of gel o ie. add 600 µl QG to a 100 mg gel piece Incubate at Room Temp for 10 mins, vortexing regularly until gel piece is dissolved. To each tube add 2 volumes of isopropanol per volume of gel and mix by pipetting. o ie. add 200 µl isopropanol to a 100 mg gel piece Apply to column and spin at max speed 30 sec Pour flowthrough back on to column and spin at max speed 30 sec Repeat until entire volume has been passed through column Add 500 µl Buffer QG and spin at max speed 30 sec Add 750 µl Buffer PE and spin at max speed 45 sec Spin empty column at max speed 1 min Transfer column to new 1.5 ml tube Aspirate around purple ring inside column Allow to air dry 1 min Apply 38 µl Buffer EB and let stand 1 min (accounts for loss of 2 µl volume during elution) Spin at max speed 1 min and discard column 10

12 Pippin Prep Size Selection Using Sage Science s Pippin Prep helps standardize library size selection and most importantly vastly increases yield over the normal gel extraction technique. Turn on the machine by a button in the back, on the bottom right. The machine does not catch your mistakes, so carefully follow the directions and be aware of what you are doing. CAUTION: some gels contain Ethidium Bromide, so wear gloves at all times. Components 2% EF (Ethidium Free) Agarose Gel Cassette (Sage Science CEF-2010) OR 2% Agarose Gel Cassette (Sage Science CSD-2010) Loading Solution (in 4 o C) Marker (ladder): 2% EF use Marker E, 2% use Marker B (in 4 o C) Electrophoresis Buffer (Clear for 2% EF and Brown for 2%) Procedure 1. Remove marker and loading solution from refrigerator and let stand at Room Temp for 20 mins 2. Add 10 µl of loading solution to 30 µl DNA sample from the previous step. Mix by vortex and spin. 3. Remove gel cassette from foil pack and Visually Inspect the Cassette: Inspect the gel columns. Look for obvious breakage of the agarose column in each channel. If there is breakage, do not use the lane at all. Remaining lanes can be used Inspect the levels of buffer in all buffer chambers. Reservoirs should be nearly full, so if any buffer level appears less, fill with spare electrophoresis buffer after tape is removed. 11

13 Pippin Prep Size Selection (cont.) Example of a bubble in the Optical region Inspect bottom of cassette for bubbles in the detection region of the gel columns. If a bubble is present, do not use the lane as a reference (marker lane). The lane can be used for sample collection. Flat bubbles on the top surface of the gel will have no effect on optical detection or purification, so the lane can be used for either markers or samples. 4. Dislodge bubbles from behind the elution wells. Tilt the cassette samples well side down and tap the elution well side to release any trapped bubbles. 5. Place gel cassette into the optical nest. Keep the cassette slightly tilted down so that the bubbles by the elution well do not return. 6. Remove the white tabbed adhesive strips from the cassette by grabbing the white tabs of the tape and pulling the strips firmly and slowly toward the front of the Pippin Prep. If there are any unused lanes, save the adhesive strips by placing them on the foil wrapper to reseal the gel after the run. 7. Remove the buffer from all the elution wells and replace with 40 µl of fresh electrophoresis buffer. Make sure the pipette tip is all the way at the bottom of the well and then dispense the buffer while pulling up with the pipette. 8. Check the buffer level in the sample wells. The wells should be completely filled to the top with buffer and if any wells are under-filled, and then top them off with additional electrophoresis buffer. 9. Perform the continuity TEST. Close the lid and press the Test button located in the lower right area of the Main screen. The test routine runs automatically and measures the current in each separation and elution channel. If continuity tester indicates PASS for each separation and elution channel, then click RETURN and proceed to the next step. If the tester indicates FAIL, the lane and channel (separation or elution) that are out of range will be highlighted with an orange color and do one of the following steps: If a separation lane is out of specified range, try restarting the software and trying again. In addition, check the levels of the buffer in the sample wells and anode buffer chamber. If the lane fails again, do not use lane and notify Sage Science of this problem. If an elution lane is out of specified range, remove buffer from the elution well and replace with 40 µl of fresh electrophoresis buffer. Retest. If it fails again, try replacing all the elution wells with fresh electrophoresis buffer and then Retest. If the lane fails again, it maybe be used as a reference (marker) lane, but may not be used to collect a sample. 12

14 Pippin Prep Size Selection (cont.) 10. Replace the white tabbed adhesive strip over the elution wells with a new piece of tape that is next to the machine. Start the tape at the corner of the elution modules, just past the optical region, and make sure it covers the elution well, small hole in gel, and rectangle part of the cathode chamber. No tape should be in the optical region. Optional: Score the tape between each elution well with a razor, to help prevent sample cross contamination from the wicking of droplets when peeling off the adhesive later. 11. Press the tape over the elution wells firmly with a blunt smooth object (finger or sharpie), to ensure a good seal. 12. Remove 40 µl of buffer from the sample wells. Take care not to pierce the agarose with the pipette tip as there is gel on all sides and bottom of the sample well. There should be some buffer (~30 µl) left in the well. Wait 30 sec and check to make sure no wells completely refill with buffer. If a lane does refill, take out an additional 20 µl of buffer. If the lane keeps refilling with buffer, then use this lane as the reference (marker) lane or Input sample lane and be cautious to use the lane for a TF ChIP sample. In step 14, load this well last by removing 40 µl of buffer and quickly adding the marker or sample. 13. Set Up Size Selection Protocol: Open up the Protocol Editor tab Click Load if using a previously saved protocol, if not continue to next step Select Cassette Type: o For 2% EF Agarose Gel Cassette select 2%EF Marker E V2 o For 2% Agarose Gel Cassette select 2% Marker B No Overflow Detection Select Mode for each Lane: o Ref for the marker o Range for the samples o Off for the lanes not being run Enter Size Range: o For Genomic DNA Adapters; BP Start: 180, BP End: 270, BP Pause: 220 o For Multiplexed Adapters; BP Start: 170, BP End: 260, BP Pause: 210 o For TruSeq Adapters; BP Start: 230, BP End: 320, BP Pause: 270 Enter Sample ID Template Names Make sure the BP Range Flag is Broad and the Pause Enabled is highlighted yellow Click Save As at the bottom right of the screen to save your protocol. Enter Protocol Name, whatever you like. It automatically stamps it with date and time. If you make any changes to the protocol, hit Save from now on. Click Main tab to get back to the main screen. Your protocol should appear there now. 14. Load 40 µl of sample into their respective sample well. Once again, take care not to pierce the agarose with the tip. Do not be concerned if the sample well slightly overfills. The density of the sample will allow it to sink before it can flow out of the well. 15. Press the Start button. 16. If any mistakes were made, like adding the wrong marker or selecting the wrong cassette type, errors can be caught by checking on the progress of the run. Make sure the ladder peaks come up when they are supposed to (see markers below). The machine will continue to run and not PAUSE, unless it can detect the marker. Worst case, Stop the run and rerun it in Manual Mode to collect fractions. 13

15 Pippin Prep Size Selection (cont.) 2% EF Agarose Gel Cassette Marker E 2% Agarose Gel Cassette Marker B 17. After ~55min the run should be paused and the RESUME button will be available. If the run is still progressing and the Elute boxes are orange, that means it is still collecting the first fraction and just wait until it pauses. If the run is still progressing and the Separate boxes are green, that means it has not reached the collection BP Start size or there was a mistake. 18. Remove the adhesive over the elution wells, collect the entire volume (~40 µl), and place into a new Eppendorf tube for each sample/lane. 19. Using a p10 pipette and thin tip, make sure to get into the corners to get every last drop. Optional: Rinse each elution well with 5-10 µl of Elution Buffer and put into corresponding tube. 20. Add 40 µl of fresh electrophoresis buffer to the elution well and Replace Adhesive. 21. Click the RESUME button. 22. After 10-15min return to machine and make sure the Elute boxes are not orange and the 300bp marker has appeared. Manually stop the run by clicking the STOP button. 23. Remove the adhesive over the elution wells, collect the entire volume (~40-60µl), and place into a fresh Eppendorf tube for each sample/lane. This is your top band equivalent, and is a failsafe measure. Throw out Gel, and do not leave it in the machine. 14

16 Enrich the Adapter-Modified DNA Fragments by PCR This protocol PCR amplifies the size selected DNA. Follow step 5a for the optimal cleanup option to avoid having unused primer still around after cleanup (see OK MP Library on pg.17). If Agencourt Ampure XP Beads are not available then follow step 5b. Cleanup Method Agencourt Ampure XP Beads Freshly prepared 75% Ethanol Optional: Qiagen MinElute PCR Purification Kit Sample Prep Kit Components Phusion polymerase 5x Phusion HF buffer 10 mm dntp mix PCR primer 1.1 or Multiplex PCR Primer 1 PCR primer 2.1 or Multiplex PCR Primer 2 with Index Master Mix (MM) Kit Components Phusion HF PCR Master Mix (Optional) PCR primer 1.1 or Multiplex PCR Primer 1 PCR primer 2.1 or Multiplex PCR Primer 2 with Index Procedure 1. Prepare the following PCR mix: x1 x5 5x Phusion HF buffer 10 µl 50 µl dntp mix 1.5 µl 7.5 µl PCR primer µl 5 µl PCR primer µl 5 µl Phusion polymerase 0.5 µl 2.5 µl 14 µl 2. 2% Agarose Size Selection: Add 14 µl of PCR mix to 36 µl of DNA sample. Pippin Prep Size Selection: Add 14 µl of PCR mix to ~40 µl of DNA sample. Optional: The PCR reaction can be scaled up to 100 µl by adding H 2 O until the DNA sample volume is 72 µl. Double the PCR Mix volumes above and Add 28 µl of PCR mix to 72 µl of DNA sample. OR Pippin Prep Size Selection PCR Master Mix: Add 2 µl of each PCR Primer (4 µl total) and 50 µl of Phusion HF PCR Master Mix to µl DNA sample. 3. Amplify using the following PCR protocol (solexa1): a. 30 seconds at 98 C b. 18 cycles of: 10 seconds at 98 C 30 seconds at 65 C 30 seconds at 72 C c. 5 minutes at 72 C d. Hold at 4 C 15

17 Enrich the Adapter-Modified DNA Fragments by PCR (cont.) 4. Remove the Ampure XP Beads or MinElute Column from 4 o C and let sit at Room Temp for ~30min. 5a. Purify using Agencourt Ampure XP Beads: Make sure beads came to Room Temp before proceeding Vortex/mix the beads until they are well dispersed, and keep doing so every couple of samples Add 90 µl of Ampure XP beads for every 50 µl PCR volume and mix by pipetting at least 10x Incubate the tubes at Room Temp for 12 min Place tubes on magnetic stand and let sit for 2 min or until the liquid appears clear Remove and discard the majority of the supernatant from each tube Add 200 µl 75% Ethanol and let it incubate on the stand for 1 min and then Discard Ethanol Repeat Ethanol wash one more time, making sure to completely remove all traces of Ethanol Let stand at Room Temp for 5-10 min to dry and remove all Ethanol Remove from magnetic stand and resuspend the dried beads in 16 µl EB Mix by pipetting 10x and Incubate at Room Temp for 5 min Place tubes on magnetic stand and let sit for 2 min or until the liquid appears clear Transfer 15 µl of the supernatant to a new tube 5b. Purify using MinElute PCR Purification Kit: If the Pippin Prep was used, adjusting the ph is necessary to lower the ~8-9 ph of the Electrophoresis Buffer to ensure optimal binding of the DNA to the column. Add 5 volumes of Buffer PB to 1 volume of the PCR reaction (ie add 250 µl Buffer PB to 50 µl PCR) and mix by pipetting Add 1 µl of ph Indicator for every 250 µl Buffer PB added If orange or purple in color, Add 2 µl of 3 M sodium acetate (NaOAc ~ph5.5) for every 250 µl PB added. If it does not turn bright yellow, then add NaOAc in 1 µl increments until it does. Apply to column and spin at max speed 30 sec Pour flowthrough back on to column and spin at max speed 30 sec Add 750 µl Buffer PE and allow to stand 1 min Spin at max speed 45 sec and discard flowthrough Spin empty column at max speed 1 min Transfer column to new 1.5 ml tube Aspirate around purple ring inside column Allow to air dry 1 min Apply 17 µl Buffer EB and let stand 2 min Spin at max speed 1 min and discard column 16

18 Validate the Library Illumina recommends using Agilent Technologies 2100 BioAnalyzer to check the size, purity, and concentration of the library. The BioAnalyzer results below were generated using Agilent s DNA kit. If followed correctly, this protocol should not yield a Bad Library, but may still yield a Might be OK Library. Since some ChIP samples may have very low starting material or poor sonication, after 18 cycles of PCR the yield could still be too low to use. Generally a library that is 40nM or below has PCR artifacts and is not a good library. Good SR Library Good MP Library The Good Libraries to the left have high molarity and a nice narrow peak. OK MP Library The OK MP Library is broad and slightly higher in size than recommend, but can be sequenced. In addition, the library has a peak at ~80bp, which is unused PCR primers, that will not cluster to the flowcell. This peak is usually seen if the MinElute purification step was used after PCR. OK SR Library The OK SR Library can be sequenced despite having some higher junk. An explanation for this phenomenon is the presence of some ssdna that are daisy chained or clumped together based on the sequence homology of the primers. It is generated by the PCR if too many cycles of amplification are performed or if the primer concentration is too low. Might be OK Library The Might be OK Library has a low molarity and broad peak, which usually means there will be PCR bias and is not worth proceeding; however, there is a possibility it could have worked, but it will have to be sequenced to know. Bad Library The Bad Library has adapter junk at 100bp (for Genomic Adapters, it will be bp for Multiplex and TruSeq Adapters) that will cluster and thus will cause less usable reads. If the the ratio of adapter junk to library is less than 10%, the library can be sequenced. In addition, the Bad Library is broad, which could still be used if not for the adapter junk, but it is better for the analysis if the peak is narrower. 17